1. Field of the Invention
The present invention relates to a light emitting device such as a light emitting diode for use in a backlight for a display, an LED indicator, etc. and also relates to a manufacturing method for such a light emitting device.
2. Description of the Related Art
Conventionally provided in a light emitting device such as a light emitting diode (LED) having a sapphire layer and a light emitting layer formed on the sapphire layer (see Japanese Patent Laid-Open No. Hei 10-56203, for example). Such a light emitting device is manufactured by cutting a light emitting device wafer along a plurality of division lines, wherein the light emitting device wafer has a sapphire substrate as a parent substrate and a light emitting layer formed on the front side of the sapphire substrate, and the division lines are formed on the light emitting layer. Thus, the light emitting device wafer is divided along the division lines to obtain a plurality of light emitting devices.
As a method of dividing a substrate such as a sapphire substrate along the division lines, a method including laser processing is known. This method includes the steps of applying a pulsed laser beam to the substrate along the division lines to thereby form a plurality of laser processed grooves on the substrate along the division lines and next applying an external force to these laser processed grooves to thereby break the substrate along the division lines (see Japanese Patent Laid-Open No. Hei 10-305420, for example). Another method of dividing the substrate along the division lines includes the steps of applying a pulsed laser beam having a transmission wavelength to the substrate along the division lines in the condition where the focal point of the pulsed laser beam is set in the substrate to thereby form a plurality of modified layers in the substrate along the division lines in such a manner that each modified layer continuously extends along the corresponding division line and next applying an external force to the division lines where the strength of the substrate is reduced by the formation of the modified layers to thereby break the substrate along the division lines (see Japanese Patent No. 3408805, for example).